refactor(trace/api): Introduce type system for trace API

This change updates the trace API by introducing a limited type system
for the table columns. Previously, the table columns could have any
possible type representable by the JVM. With this change, we limit the
available types to a small type system.

4 files changed, 127 insertions, 60 deletions

diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt
index 3132b1d9..e9017b35 100644
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt
+++ b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt
@@ -29,7 +29,9 @@ import org.opendc.trace.*
 import org.opendc.trace.conv.RESOURCE_ID
 import org.opendc.trace.conv.RESOURCE_STATE_CPU_USAGE_PCT
 import org.opendc.trace.conv.RESOURCE_STATE_TIMESTAMP
+import java.time.Duration
 import java.time.Instant
+import java.util.*
 
 /**
  * A [TableReader] for the Azure v1 VM resource state table.
@@ -63,20 +65,22 @@ internal class AzureResourceStateTableReader(private val parser: CsvParser) : Ta
         return true
     }
 
-    override fun resolve(column: TableColumn<*>): Int = columns[column] ?: -1
+    private val COL_ID = 0
+    private val COL_TIMESTAMP = 1
+    private val COL_CPU_USAGE_PCT = 2
 
-    override fun isNull(index: Int): Boolean {
-        require(index in 0..columns.size) { "Invalid column index" }
-        return false
+    override fun resolve(name: String): Int {
+        return when (name) {
+            RESOURCE_ID -> COL_ID
+            RESOURCE_STATE_TIMESTAMP -> COL_TIMESTAMP
+            RESOURCE_STATE_CPU_USAGE_PCT -> COL_CPU_USAGE_PCT
+            else -> -1
+        }
     }
 
-    override fun get(index: Int): Any? {
-        return when (index) {
-            COL_ID -> id
-            COL_TIMESTAMP -> timestamp
-            COL_CPU_USAGE_PCT -> cpuUsagePct
-            else -> throw IllegalArgumentException("Invalid column index")
-        }
+    override fun isNull(index: Int): Boolean {
+        require(index in 0..COL_CPU_USAGE_PCT) { "Invalid column index" }
+        return false
     }
 
     override fun getBoolean(index: Int): Boolean {
@@ -91,6 +95,10 @@ internal class AzureResourceStateTableReader(private val parser: CsvParser) : Ta
         throw IllegalArgumentException("Invalid column")
     }
 
+    override fun getFloat(index: Int): Float {
+        throw IllegalArgumentException("Invalid column")
+    }
+
     override fun getDouble(index: Int): Double {
         return when (index) {
             COL_CPU_USAGE_PCT -> cpuUsagePct
@@ -98,6 +106,40 @@ internal class AzureResourceStateTableReader(private val parser: CsvParser) : Ta
         }
     }
 
+    override fun getString(index: Int): String? {
+        return when (index) {
+            COL_ID -> id
+            else -> throw IllegalArgumentException("Invalid column")
+        }
+    }
+
+    override fun getUUID(index: Int): UUID? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun getInstant(index: Int): Instant? {
+        return when (index) {
+            COL_TIMESTAMP -> timestamp
+            else -> throw IllegalArgumentException("Invalid column")
+        }
+    }
+
+    override fun getDuration(index: Int): Duration? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun <T> getList(index: Int, elementType: Class<T>): List<T>? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun <K, V> getMap(index: Int, keyType: Class<K>, valueType: Class<V>): Map<K, V>? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun <T> getSet(index: Int, elementType: Class<T>): Set<T>? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
     override fun close() {
         parser.close()
     }
@@ -131,15 +173,6 @@ internal class AzureResourceStateTableReader(private val parser: CsvParser) : Ta
         cpuUsagePct = Double.NaN
     }
 
-    private val COL_ID = 0
-    private val COL_TIMESTAMP = 1
-    private val COL_CPU_USAGE_PCT = 2
-    private val columns = mapOf(
-        RESOURCE_ID to COL_ID,
-        RESOURCE_STATE_TIMESTAMP to COL_TIMESTAMP,
-        RESOURCE_STATE_CPU_USAGE_PCT to COL_CPU_USAGE_PCT
-    )
-
     companion object {
         /**
          * The [CsvSchema] that is used to parse the trace.
diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt
index 154a37e4..456a2536 100644
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt
+++ b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt
@@ -27,7 +27,9 @@ import com.fasterxml.jackson.dataformat.csv.CsvParser
 import com.fasterxml.jackson.dataformat.csv.CsvSchema
 import org.opendc.trace.*
 import org.opendc.trace.conv.*
+import java.time.Duration
 import java.time.Instant
+import java.util.*
 
 /**
  * A [TableReader] for the Azure v1 VM resources table.
@@ -63,22 +65,26 @@ internal class AzureResourceTableReader(private val parser: CsvParser) : TableRe
         return true
     }
 
-    override fun resolve(column: TableColumn<*>): Int = columns[column] ?: -1
+    private val COL_ID = 0
+    private val COL_START_TIME = 1
+    private val COL_STOP_TIME = 2
+    private val COL_CPU_COUNT = 3
+    private val COL_MEM_CAPACITY = 4
 
-    override fun isNull(index: Int): Boolean {
-        require(index in 0..columns.size) { "Invalid column index" }
-        return false
+    override fun resolve(name: String): Int {
+        return when (name) {
+            RESOURCE_ID -> COL_ID
+            RESOURCE_START_TIME -> COL_START_TIME
+            RESOURCE_STOP_TIME -> COL_STOP_TIME
+            RESOURCE_CPU_COUNT -> COL_CPU_COUNT
+            RESOURCE_MEM_CAPACITY -> COL_MEM_CAPACITY
+            else -> -1
+        }
     }
 
-    override fun get(index: Int): Any? {
-        return when (index) {
-            COL_ID -> id
-            COL_START_TIME -> startTime
-            COL_STOP_TIME -> stopTime
-            COL_CPU_COUNT -> getInt(index)
-            COL_MEM_CAPACITY -> getDouble(index)
-            else -> throw IllegalArgumentException("Invalid column")
-        }
+    override fun isNull(index: Int): Boolean {
+        require(index in 0..COL_MEM_CAPACITY) { "Invalid column index" }
+        return false
     }
 
     override fun getBoolean(index: Int): Boolean {
@@ -93,6 +99,13 @@ internal class AzureResourceTableReader(private val parser: CsvParser) : TableRe
     }
 
     override fun getLong(index: Int): Long {
+        return when (index) {
+            COL_CPU_COUNT -> cpuCores.toLong()
+            else -> throw IllegalArgumentException("Invalid column")
+        }
+    }
+
+    override fun getFloat(index: Int): Float {
         throw IllegalArgumentException("Invalid column")
     }
 
@@ -103,6 +116,41 @@ internal class AzureResourceTableReader(private val parser: CsvParser) : TableRe
         }
     }
 
+    override fun getString(index: Int): String? {
+        return when (index) {
+            COL_ID -> id
+            else -> throw IllegalArgumentException("Invalid column")
+        }
+    }
+
+    override fun getUUID(index: Int): UUID? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun getInstant(index: Int): Instant? {
+        return when (index) {
+            COL_START_TIME -> startTime
+            COL_STOP_TIME -> stopTime
+            else -> throw IllegalArgumentException("Invalid column")
+        }
+    }
+
+    override fun getDuration(index: Int): Duration? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun <T> getList(index: Int, elementType: Class<T>): List<T>? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun <T> getSet(index: Int, elementType: Class<T>): Set<T>? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
+    override fun <K, V> getMap(index: Int, keyType: Class<K>, valueType: Class<V>): Map<K, V>? {
+        throw IllegalArgumentException("Invalid column")
+    }
+
     override fun close() {
         parser.close()
     }
@@ -140,19 +188,6 @@ internal class AzureResourceTableReader(private val parser: CsvParser) : TableRe
         memCapacity = Double.NaN
     }
 
-    private val COL_ID = 0
-    private val COL_START_TIME = 1
-    private val COL_STOP_TIME = 2
-    private val COL_CPU_COUNT = 3
-    private val COL_MEM_CAPACITY = 4
-    private val columns = mapOf(
-        RESOURCE_ID to COL_ID,
-        RESOURCE_START_TIME to COL_START_TIME,
-        RESOURCE_STOP_TIME to COL_STOP_TIME,
-        RESOURCE_CPU_COUNT to COL_CPU_COUNT,
-        RESOURCE_MEM_CAPACITY to COL_MEM_CAPACITY
-    )
-
     companion object {
         /**
          * The [CsvSchema] that is used to parse the trace.
diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
index 73978990..2294e4a4 100644
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
+++ b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
@@ -62,26 +62,25 @@ public class AzureTraceFormat : TraceFormat {
         return when (table) {
             TABLE_RESOURCES -> TableDetails(
                 listOf(
-                    RESOURCE_ID,
-                    RESOURCE_START_TIME,
-                    RESOURCE_STOP_TIME,
-                    RESOURCE_CPU_COUNT,
-                    RESOURCE_MEM_CAPACITY
+                    TableColumn(RESOURCE_ID, TableColumnType.String),
+                    TableColumn(RESOURCE_START_TIME, TableColumnType.Instant),
+                    TableColumn(RESOURCE_STOP_TIME, TableColumnType.Instant),
+                    TableColumn(RESOURCE_CPU_COUNT, TableColumnType.Int),
+                    TableColumn(RESOURCE_MEM_CAPACITY, TableColumnType.Double),
                 )
             )
             TABLE_RESOURCE_STATES -> TableDetails(
                 listOf(
-                    RESOURCE_ID,
-                    RESOURCE_STATE_TIMESTAMP,
-                    RESOURCE_STATE_CPU_USAGE_PCT
-                ),
-                listOf(RESOURCE_STATE_TIMESTAMP)
+                    TableColumn(RESOURCE_ID, TableColumnType.String),
+                    TableColumn(RESOURCE_STATE_TIMESTAMP, TableColumnType.Instant),
+                    TableColumn(RESOURCE_STATE_CPU_USAGE_PCT, TableColumnType.Double),
+                )
             )
             else -> throw IllegalArgumentException("Table $table not supported")
         }
     }
 
-    override fun newReader(path: Path, table: String, projection: List<TableColumn<*>>?): TableReader {
+    override fun newReader(path: Path, table: String, projection: List<String>?): TableReader {
         return when (table) {
             TABLE_RESOURCES -> {
                 val stream = GZIPInputStream(path.resolve("vmtable/vmtable.csv.gz").inputStream())
diff --git a/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt b/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
index 263d26ce..932858f8 100644
--- a/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
+++ b/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
@@ -60,7 +60,7 @@ class AzureTraceFormatTest {
         val reader = format.newReader(path, TABLE_RESOURCES, null)
         assertAll(
             { assertTrue(reader.nextRow()) },
-            { assertEquals("x/XsOfHO4ocsV99i4NluqKDuxctW2MMVmwqOPAlg4wp8mqbBOe3wxBlQo0+Qx+uf", reader.get(RESOURCE_ID)) },
+            { assertEquals("x/XsOfHO4ocsV99i4NluqKDuxctW2MMVmwqOPAlg4wp8mqbBOe3wxBlQo0+Qx+uf", reader.getString(RESOURCE_ID)) },
             { assertEquals(1, reader.getInt(RESOURCE_CPU_COUNT)) },
             { assertEquals(1750000.0, reader.getDouble(RESOURCE_MEM_CAPACITY)) },
         )
@@ -75,8 +75,8 @@ class AzureTraceFormatTest {
 
         assertAll(
             { assertTrue(reader.nextRow()) },
-            { assertEquals("+ZcrOp5/c/fJ6mVgP5qMZlOAGDwyjaaDNM0WoWOt2IDb47gT0UwK9lFwkPQv3C7Q", reader.get(RESOURCE_ID)) },
-            { assertEquals(0, reader.get(RESOURCE_STATE_TIMESTAMP).epochSecond) },
+            { assertEquals("+ZcrOp5/c/fJ6mVgP5qMZlOAGDwyjaaDNM0WoWOt2IDb47gT0UwK9lFwkPQv3C7Q", reader.getString(RESOURCE_ID)) },
+            { assertEquals(0, reader.getInstant(RESOURCE_STATE_TIMESTAMP)?.epochSecond) },
             { assertEquals(0.0286979, reader.getDouble(RESOURCE_STATE_CPU_USAGE_PCT), 0.01) }
         )